HTML/multihightlighter problem

I have a php file quite large, include.php, 247k.
When I load it the HTML highlighter loads, all other php files loads with the HTML multihighlighter. This means the Code Explorer window does not populate so I have to 1.change highlighter, refresh and sort Code Explorer each time I open this file.

Strange thing is that this file does not have any HTML, its just lots of php functions and defines.